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Messages - DuncanDoenitz

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1
Need to play Devil's advocate here BillO; the proof is not in this particular pudding. 

The reason for the 1920s/30s routing was, as you say, to accommodate the relatively short range of the aircraft involved (and incidentally goes some way to explaining the current hodge-podge of middle-east politics, as the British Empire ran roughshod over emirates and sheikhdoms in order to provide an air-route to British southern Africa and to India). 

Your Directflights map is not an air-route at all, its a travel agent's illustration of a hypothetical link between the 2 cities, in the same way that the London Underground Map joins Waterloo to Paddington.  Its not a navigational map.  If you look at a tracking site like Flightradar24 you'll find that the normal route is typically Balkans, eastern Med, Egypt, northern Red Sea, Ethiopea, Kenya, Tanzania, and all well to the east of a Great Circle.  The reason for this is to related to common sense as well as insurance requirements; most aviation insurance excludes flight over war-zones, rogue-states and specifically some countries such as North Korea, Libya, Yemen.  Hence, very similar to Imperial Airways, in fact, but in hours rather than days, and not a pith-helmet in sight. 

I agree 100% with your concept of modern air-routes generally being more direct, but you'll likely be looking at oceanic examples to get your point over.  Glad you're feeling better btw. 

2
Science & Alternative Science / Re: New Report on WTC 7
« on: February 19, 2024, 08:56:49 PM »

Google search - "how much fuel did ua 175 carry"

1st up = "UA 175 was also a Boeing 767-200ER and had also left Boston, bound for Los Angeles. It flew into WTC 2 carrying about 9,100 gal (62,000 lb) of jet fuel, evenly distributed between the inboard portions of the left and right wing tanks."

That is less than 10,000.

Your "book," is way, way off...perhaps in the section called "fiction."


So, "62,000 lb ........ that is less than 10,000".  Please explain.  Are you introducing gallons into this debate, when jet fuel is measured by mass, just to maintain your assertion that Mahogany is a liar? 


3
Science & Alternative Science / Re: New Report on WTC 7
« on: February 19, 2024, 07:57:12 PM »
Both 767s were destined for LAX.  According to Mr Google, a 767 uses around 13,000 pounds of fuel per hour.  Flight time of 5 hours from passing NY, plus 40 min reserves, would suggest that each 767 was carrying around 70,000 pounds of Jet-A1; kerosene if you will, at impact.  "Tens of thousands" in my book. 

Although Mahogany did not specify units, aircraft of US origin normally measure fuel load in pounds; European generally in kilograms.  Fuel quantity on commercial and military aircraft is always quantified by mass (not volume) since that is directly related to its calorific value. 

Can you be a little more specific about his alleged lie? 

4
Philosophy, Religion & Society / Re: Trump
« on: February 18, 2024, 10:06:03 PM »
"When they came for the Estonians, I was not Estonian, so I did nothing". 

And so on, and so forth. 

5
Science & Alternative Science / Re: New Report on WTC 7
« on: February 18, 2024, 09:42:34 PM »
Titled ".... WTC BUILIDING 7 ..." (sic). 

Obviously a critique with this level of peer-review deserves our full attention. 

6

Yes they are.

https://edition.cnn.com/style/article/blue-marble-photo-50th-anniversary-snap-scn/index.html
[/quote]


Quote
The iconic photo, known as “Blue Marble,” was taken by NASA astronauts Eugene “Gene” Cernan, Ronald Evans and Harrison Schmitt on December 7 using a Hasselblad camera and a Zeiss lens, about 45,000 kilometers (28,000 miles) away from home, as the Apollo 17 crew made its way to the moon.


Quote
"Oh my God, look at that picture over there! There's the Earth coming up. Wow, is that pretty!" Bill Anders shouted at fellow astronaut Jim Lovell. "You got a colour film, Jim? Hand me a roll of colour, quick, would you?"
"That's a beautiful shot," said Lovell as Anders clicked the shutter and captured what has become one of the world's most famous photographs.

There's little doubt that the Earthrise image has been chopped about and digitally altered to enhance its impact in the modern age, but it was first published in 1969.  Adobe Photoshop was developed by Thomas Knoll, born 1960.  You think maybe NASA saw his potential and brought him onboard at age 9?

7
Ferguson's Map; indeed.  Other brands also available.

Is it not clear to you that I am not debating the multitude of possible forms of map, but directly Action80's contention that the Earth is flat, "everywhere (he) goes". 

Like his desk.  And most of the maps. 


(Oh, and "zealot" btw?  Thank you; "praise indeed"). 

8
Pete, I already discounted the grain and blemishes (the mountains and valleys, if you will).  My suggestion is that Action80's desk probably has an overall curvature.  He proposed it as an analogy to the observed Earth (despite the fairly obvious difference in perspective) and stated that it is flat, but has so far provided no evidence to this effect. 

(4 years; my my).   

9
The "desk" thing is another interesting analogy.  Is it actually flat?  How do you know?  Have you measured it?  To what degree of accuracy? 

"It looks flat". 

I'm not talking about minor blemishes (maybe its wooden, does it have a grain, a surface texture)?  What I'm talking about is the overall flatness; x axis and z axis, edge to edge, corner to corner, and to a selection of datum points across its surface.  Is it cheap or of good quality.  Have you applied a certified straight-edge and measured for bow and sag?  You seem pretty sure, wonder if that's justified. 

Clever money says its not very flat at all. 

10

Indeed, I think the immediate evidence with my own eyes is more likely to be reliable than pictures from many thousands or more of miles away. I guess it's more of a philosophical position than anything else. If I perceive the Earth to be flat while I'm right up against it, why should I blindly assume that the alternative evidence is better?


This is a curious approach to science (or, indeed, philosophy).  Being close to an object certainly permits a better focus on detail, texture, and might facilitate touch, taste, smell, etc, but actually reduces the ability to perceive its shape.  To visually determine the form of an object, one actually needs to stand back from it, so that it can be seen in its entirety. 

If you were placed at a corresponding proximity to the United Nations building, the Pentagon and the Great Pyramid of Giza, you would peceive all of them to be planar in nature, but have no idea whatever of their shape. 

11
Philosophy, Religion & Society / Re: Get a haircut, you hippie!
« on: January 25, 2024, 02:47:32 PM »
Not my country, not my legal system, not my school board and not my choice of tonsorial elegance but, ffs, what is this; the 1960s?  Isn't a State court a rather heavy steamhammer against bad hair?  Jeepers, if your hair/attire/adornments aren't endangering or offending the public, what's the problem? 

12
Science & Alternative Science / Re: Do rockets push off the air?
« on: December 11, 2023, 03:25:00 PM »
So, the rifle bullet thing; 

https://www.uu.edu/dept/physics/scienceguys/2002Sept.cfm

Union University uses a machine gun as an example of a closed system. 

13
Science & Alternative Science / Re: Do rockets push off the air?
« on: December 10, 2023, 11:59:57 PM »
@Action80.  A system can comprise several entities.  For example the Joule Experiment, which you sometimes quote, comprises a cylinder, a gas, and (depending on the form used) a piston.  All Markjo is suggesting, and which you apparently find derisible, is that some of these components within the sysem can form a force-pair.  The system as a whole is not "acting against itself", but 2 independant entities within the CLOSED system acting against each other.   

Whilst I'm here, can I ask what you believe the nature of the "plume" to be?  By that, I mean is it a gas, does it have substance, does it have mass?  Would you agree that it is formed from the exhaust material of the rocket motor?  Would you agree that, as it is constantly being generated by the motor, that it must be dispersing at an equal rate?  Where is it going? 

Finally, and this is not part of the debate though it's something another couple of people have mentioned; I've no idea of your education level, nor indeed of any of the correspondents on this thread with the possible exception of RonJ who, like myself, says he is a Licensed Aircraft Maintenance Technician.  What I believe, however, is that everyone debating with you is expressing genuinely held opinions.  Some people may have misunderstood what they have learnt, and everyone seems to have misread what you have written, to the extent that we talk BS, make false claims, lie, strawman and gaslight.  You, on the other hand, are a paragon of truth, despite making repeated claims about the voracity of the "plume" thing, and how it is widely accepted by jet engine manufacturers and your nephew (though entirely without any citations to that effect).  I wonder if the disrespect and aggression shown in your replies is founded in a lack of confidence in your stated opinions. 

Without exception I, and the other correspondents, have treated you with utmost respect.  Like a closed system, it would be nice if this were recipricated. 


14
Science & Alternative Science / Re: Do rockets push off the air?
« on: December 09, 2023, 08:03:50 PM »


And yes, a force pair is still required. A closed system cannot form a force pair internal to itself. In the case of both jets and rockets, that force pair can only be formed with an outside environment that has measurable air pressure. The rocket can form a working plume in an environment that has less air pressure than a jet (jets are probably capped at an altitude of of 15 miles or so), probably at around 190,000 ft. or so.


Better check again the definition of a Closed System; it is entirely isolated from its environment. 

A rifle cartridge is, and remains, a closed system; bullet goes one way, case and rifle go the other.  Force pair.  Muzzle blast irrelevant.   

A rocket motor is a closed system; combustion gases go one way, motor goes the other.  Force pair.  Plume irrelevant. 

15
Science & Alternative Science / Re: Do rockets push off the air?
« on: December 08, 2023, 02:42:06 PM »
Whilst I echo Dr V-N's sentiments (and call me Mr Cynical) I am curious to what extent A80's nephew is on-board with this idea.  ("My uncle said what"?).  I mean, can we get an outline of how the conversation went?  Did you come up with the theory, or did you get it from  him?  When did you last discuss it?  After all, we only have your assertion that he is in agreement. 

As for General Electric and Pratt & Whitney being on the same page, without any references, this adds a whole 'nother stage of incredulity. 

16
Science & Alternative Science / Re: Do rockets push off the air?
« on: December 08, 2023, 02:06:10 PM »


So, all internal...

And yet all the arrows in Figure 1-1 show the exhaust traveling to to the rear.

If it truly was all internal, then the thrust would be traveling to the front, like some other jokers like to claim here.



Got the correction; thanks.  This is a simplified diagram of the gas flow through the engine; it does not illustrate thrust.  It shows air being inducted from the left, compressed and impelled centrifugally by the compressor, diffused and entering the combustion chamber (to the right), passing though the turbine and exiting (to the right).  (Incidentally, the fact that the intake is to the left is just a convenience.  Many engines draw their air from all around, it doesn't matter.  The only important vector is that exhaust goes right, reactive thrust goes left). 

It is a simplified diagram is explaining the gas path.  To the target audience, the fact that thrust acts to the left does not require explanation.  Why would any of the arrows point left? 

An equivalent diagram for a road vehicle might show the engine, pistons, transmission and wheels going round.  The fact that the wheels try to push the road backwards does not need to be explained. 


17
Science & Alternative Science / Re: Do rockets push off the air?
« on: December 08, 2023, 09:36:00 AM »
Exhaust gas accelerates right.  Reaction applies a force left.  Force pair.  Can you specify where the RR Book denies this? 

And going back a couple of posts, can you clarify you meant Fig 1.5?  That's a garden sprinkler. 

18
Science & Alternative Science / Re: Do rockets push off the air?
« on: December 08, 2023, 08:29:26 AM »

It doesn't matter what your source claims, there is a plume related to all jets and rockets (i.e., we see what is typically called a contrail), and that plume reacts with the pressurized external environment to form a force pair, which results in movement. No force pair, no movement.

The "source" which designs, develops and manufactures jet engines, refuted by Action80's superior insight.  And possibly his nephew. 

19
Science & Alternative Science / Re: Do rockets push off the air?
« on: December 07, 2023, 11:20:13 PM »
Yes, I have and he understands that a pressurized environment must exist for a plume to form.

Do his superiors and the engineers that designed the equipment he works on understand it?
Of course they do.

If he were to ask the people who trained him about rockets and vacuums what would they say?
Pretty much the same thing I am.

Are you smarter than them or are they lying to hide the truth?
Lying about what?


You have an admirable confidence that:
a.   You have understood what your nephew means, and vice versa.
b.   You nephew has fully understood what he has been taught. 
c.   The jet engine designers, engineers and technicians are also in accordance with you. 

However;

http://www.valentiniweb.com/piermo/meccanica/mat/Rolls%20Royce%20-%20The%20Jet%20Engine.pdf

This is a link to a pdf version of a go-to publication in the UK, and also much of the English-speaking world.  It is called "The Jet Engine" (ISBN 0 902121 2 35) and its published by Rolls Royce, who know a couple of things about them.  The book is standard reading for anyone in the UK who is embarking on a career in aircraft engines.  It outlines the principles of theory, design, construction and maintnenane, and not just of Rolls Royce products. 

I draw your attention to Part 1 "Basic mechanics", page 2, Paras 6 thru 9:

6. Jet propulsion is a practical application of Sir
Isaac Newton's third law of motion which states that,
'for every force acting on a body there is an opposite
and equal reaction'. For aircraft propulsion, the 'body'
is atmospheric air that is caused to accelerate as it
passes through the engine. The force required to
give this acceleration has an equal effect in the
opposite direction acting on the apparatus producing
the acceleration. A jet engine produces thrust in a
similar way to the engine/propeller combination. Both
propel the aircraft by thrusting a large weight of air
backwards (fig. 1-3), one in the form of a large air
slipstream at comparatively low speed and the other
in the form of a jet of gas at very high speed.
7. This same principle of reaction occurs in all forms
of movement and has been usefully applied in many
ways. The earliest known example of jet reaction is
that of Hero's engine (fig. 1-4) produced as a toy in
120 B.C. This toy showed how the momentum of
steam issuing from a number of jets could impart an
equal and opposite reaction to the jets themselves,
thus causing the engine to revolve.
8. The familiar whirling garden sprinkler (fig. 1-5) is
a more practical example of this principle, for the
mechanism rotates by virtue of the reaction to the
water jets. The high pressure jets of modern firefighting equipment are an example of 'jet reaction',
for often, due to the reaction of the water jet, the hose
cannot be held or controlled by one fireman. Perhaps
the simplest illustration of this principle is afforded by
the carnival balloon which, when the air or gas is
released, rushes rapidly away in the direction
opposite to the jet.
9. Jet reaction is definitely an internal phenomenon
and does not, as is frequently assumed, result from
the pressure of the jet on the atmosphere.
In fact, the
jet propulsion engine, whether rocket, athodyd, or
turbo-jet, is a piece of apparatus designed to
accelerate a stream of air or gas and to expel it at
high velocity. There are, of course, a number of ways .....

I can find no mention of "plume" in the book, but be my guest.  Perhaps you could discuss this further with your nephew. 

Edit; my Bold, btw.

20
Science & Alternative Science / Re: Do rockets push off the air?
« on: December 07, 2023, 08:39:26 PM »
@Action. First of all respect to your nephew; serving his country in the military and then transferring those learned skills to the airline industry.  Similar career path to mine, though in the UK. 

Following up on Dr v-N, I wonder if you have actually discussed jet engine theory with your nephew, or whether you are just throwing in random relatives in the hope that it will lend your argument some kudos.  My sister is a nurse, but that wouldn't reinforce any argument I might make about Covid. 

And I don't like labouring a point, but you still haven't explained how the presence of a plume lends thrust to the jet/rocket. 

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